There are more, these just happen to be the more popular ones this year:

PUMS sports center ( FREE!!!)

Address: ul. Rokietnicka 5 D,

Tel./fax: 061 8614208; tel. 061 869 44 48

Open: Monday – Sunday 9am-18:00 +

Activities: Aerobics, basketball, weight room, tennis (You must purchase a 3zl
stamp for each hour you want to rent out the courts. The tickets can be bought
between 8:00 and 13:00 M-F in the main office. You must have your own tennis
balls and racquets)